Core Unit- Gnotobiology and Diagnostic Laboratory Services The core unit will serve all projects in a highly interactive and collaborative basis. Four basic types of services will be provided. 1. Technical Services for Gnotobiology- This will include germ free isolator fabrication, modification and design and set-up as required for rodents. Technical expertise and support will be provided for the design, construction, manipulation and maintenance of special HEPA filtered enclosures for housing immunocompromised dogs and primates. Decontamination and logistical support will be provided, as well as autoclaving and decontaminating equipment, food, water, and other supplies. Cesarean derivation of rodents and other special manipulation will be provided. 2. Housing for Germ free and Gnotobiotic Rodents- Routine husbandry (feeding, watering, cage changing, etc.) will be provided for all rodents in germ free isolators. Similar husbandry and care will be provided for SCID rodents on study while housed in special HEPA filtered enclosures in the Department of Biology animal facility. The core will coordinate with University Laboratory Animal Resources on animal care related activities as required. 3. Diagnostic Laboratory Services- Existing research laboratory facilities in Laboratory Animal Medicine and in Veterinary Pathobiology will provide diagnostic support. This support will characterize and assure microbial status of animals used in the studies and will survey and assure appropriate environmental conditions for germ free isolators, HEPA filtered containment enclosures, and other areas in which animals are housed. 4. Administrative Support- The core will provide administrative support to project leaders and will coordinate all animal care and use matters with appropriate university offices.